JP6549268B1 - Heat exchangers for aircraft engines - Google Patents

Abstract

A heat exchanger for an aircraft engine that can be adapted to weight restrictions and dimensional restrictions and that can improve the amount of heat exchange without increasing pressure loss. A heat exchanger 100 (a heat exchanger for an aircraft engine) includes a core portion 1 through which a fluid to be cooled flows, and a plurality of plate-like radiating fins 2 provided on a surface 10 of the core portion 1. Is provided. The heat radiating fin 2 includes a first portion 21 rising from the surface 10 of the core portion 1, a second portion 22 disposed on the tip side of the first portion 21 and having a thickness smaller than that of the first portion 21, and a first portion 21 and the connection part 23 inclined with respect to the 2nd part 22 are included. In the radiating fin 2, the ratio y / Y of the height y from the surface 10 of the core portion 1 to the formation position of the connecting portion 23 with respect to the total height Y of the radiating fin 2 from the surface 10 of the core portion 1 is 0. It is formed so as to satisfy the relationship of 34 <y / Y <0.64. [Selection] Figure 4

Description

  The present invention relates to a heat exchanger for an aircraft engine, and more particularly to a heat exchanger for an aircraft engine equipped with heat dissipating fins.

  DESCRIPTION OF RELATED ART Conventionally, the heat exchanger for aircraft engines provided with a radiation fin is known (for example, refer patent document 1).

  Patent Document 1 discloses a heat exchanger for an aircraft engine including a main body (core portion) for circulating a fluid to be cooled, and a plurality of radiation fins provided on the outer surface of the main body. The heat exchanger has a plate-like shape whose main body is curved along a curved surface (such as the inner circumferential surface of a fan casing) in an aircraft engine, and is cooled by heat exchange with air flowing in the aircraft engine. It is a heat exchanger that cools the fluid and is called a surface cooler. Each radiation fin is provided so as to protrude from the surface of the main body toward the inner diameter direction or the outer diameter direction in the engine, and has a flat plate shape. The fluid to be cooled is, for example, lubricating oil circulated to an aircraft engine or a generator in the aircraft.

Patent No. 5442916 gazette

  Although not described in the above-mentioned Patent Document 1, in the heat exchanger for aircraft use, the weight restriction and the size restriction are severe, and there is a processing restriction when actually forming the radiation fin, so the main body (core portion) There are limitations on the height of the heat dissipating fins, the number of heat dissipating fins (pitch between the heat dissipating fins), and the total weight of all the heat dissipating fins. Therefore, it has been difficult to improve (increase) the amount of heat exchange. In addition, even if the amount of heat exchange is improved (increased), if the pressure loss due to each radiation fin increases, it affects the performance of the aircraft engine, so heat exchange is performed without increasing the pressure loss compared to the conventional case. It is also desirable to improve the quantity.

  The present invention has been made to solve the problems as described above, and one object of the present invention is to meet the weight restriction and the size restriction, and to change the amount of heat exchange without increasing the pressure loss. To provide a heat exchanger for an aircraft engine that can improve (increase).

  In order to achieve the above object, as a result of intensive investigations by the inventors of the present application, the thickness of the radiation fin is made different between the tip end side and the root side, focusing on the heat conduction inside the radiation fin. It has been found that the amount of heat exchange can be improved while meeting the weight and size restrictions. Then, the present inventors further found that the degree of improvement (increase) in the amount of heat exchange changes depending on the position of the connection portion where the thickness of the heat radiation fin changes, and derived a suitable position range of the connection portion. That is, a heat exchanger for an aircraft engine according to the present invention is a heat exchanger for an aircraft engine that exchanges heat with an air flow in the aircraft engine, the core portion for circulating the fluid to be cooled, the surface of the core portion And a plurality of plate-like heat dissipating fins provided on the surface of the core portion, the heat dissipating fins being disposed closer to the tip than the first portion and having a smaller thickness than the first portion. A second portion and a connection portion inclined with respect to the first portion and the second portion connecting between the first portion and the second portion, and relative to the total height Y of the radiation fin from the surface of the core portion The ratio y / Y of the height y from the surface of the core portion to the formation position of the connection portion is formed to satisfy the relationship of 0.34 <y / Y <0.64. In addition, the formation position of a connection part is a center position of the height direction of the inclined connection part. Similarly, in the case of having a plurality of connection portions, the central position in the height direction of each connection portion is taken as the formation position.

  In the heat exchanger for an aircraft engine according to the present invention, the thickness of the first portion on the base side in contact with the high temperature core portion can be relatively increased by the above configuration to increase the heat conduction amount inside the radiation fin Since it can do, the amount of heat exchange of a heat transfer fin can be made to increase. In addition, the pressure loss can be reduced while securing the amount of heat exchange by relatively reducing the thickness of the second portion on the tip side where a sufficient amount of heat exchange can be obtained by the airflow in the high-speed aircraft engine. it can. And based on the simulation result mentioned later, by forming a radiation fin so that ratio y / Y may satisfy the relation of 0.34 <y / Y <0.64, it is a rectangular section of the same weight and the same height. It becomes possible to realize the improvement effect of the amount of heat exchange of about 2% or more (about 1.8% or more) compared with the radiation fin. As described above, according to the present invention, the amount of heat exchange can be improved (increased) while being compatible with the weight restriction and the size restriction, and without increasing the pressure loss.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the radiation fin has a ratio X / x of the thickness X of the first portion to the thickness x of the second portion of 1.0 ≦ X / x <5.4. It is formed to satisfy the relationship of Thus, in addition to the above findings, the inventors of the present invention have heat exchange in the range of the ratio (X / x) of the thickness of the second portion to the first portion of 1.0 <X / x <5.4. We found that the amount improved. Thereby, based on the simulation result mentioned later, compared with the radiation fin of the rectangular cross section of the same weight and the same height, it becomes possible to aim at improvement of the heat exchange amount, without increasing a pressure loss. Also, when the thickness ratio (X / x) is in the range of 1.0 <X / x <5.4, the difference in thickness between the second portion and the first portion does not become too large, so heat is actually dissipated The processability (easiness of processing) of the heat dissipating fin at the time of forming the fin can be secured.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the radiation fin has a length h of the inclined connecting portion in the height direction of the radiation fin with respect to the total height Y of the radiation fin from the surface of the core portion. The ratio h / Y is formed to satisfy the relationship of 0 <h / Y <0.64. Thus, in addition to the above findings, the inventors of the present invention have a large amount of heat exchange when the ratio (h / Y) of the formation range of the connection portion at the total height of the radiation fin is 0 <h / Y <0.64. I found it to improve. Thereby, based on the simulation result mentioned later, it becomes possible to realize the improvement effect of the heat exchange amount of at least 3% or more compared with the radiation fin of the rectangular cross section of the same weight and the same height.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the radiation fin has a flat side surface on one side and an inclined side surface portion of the connecting portion on the other side surface. According to this structure, the side surface on one side of the heat dissipating fin can be formed as a simple flat surface similar to a general rectangular cross-section heat dissipating fin. And in the side surface of the other side of a radiation fin, the inclined side part can be formed and thickness of a 1st part and a 2nd part can be varied. In this configuration, for example, skive processing (processing to form a radiation fin by cutting and raising a plate-like substrate) can be adopted, so that the ease of processing can be improved, or a processing method corresponding to the shape of the radiation fin It is possible to secure the freedom of choice.

  In this case, preferably, the radiation fin has a ratio h / Y of the length h of the inclined connection portion in the height direction of the radiation fin to the total height Y of the radiation fin from the surface of the core portion is 0.20. It is formed to satisfy the relationship of <h / Y <0.50. According to this structure, the heat exchange amount is about 3.7% to about 3.7% without increasing the pressure loss as compared with the radiation fin of the rectangular cross section having the same weight and the same height based on the simulation result described later. It is possible to realize a high improvement effect near the peak of 3.8%.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the radiation fin is formed with inclined side portions of the connection portion on both side surfaces respectively. According to this structure, it is possible to obtain the radiation fin in which the inclined side surface portion is formed on each of the one side and the other side. Therefore, either side of the radiation fin with respect to the swirling air flow in the aircraft engine Does not make a big difference in heat exchange performance. Therefore, unlike the case where the radiation fin in which the inclined side portion is formed on only one side is provided, the influence of the direction of the radiation fin on the direction of the air flow in the aircraft engine can be suppressed, so the design of the heat exchanger Can be done easily.

  In this case, preferably, the radiation fin has a ratio h / Y of the length h of the inclined connection portion in the height direction of the radiation fin to the total height Y of the radiation fin from the surface of the core portion: 0 <h It is formed to satisfy the relationship of /Y<0.40. According to this structure, the heat exchange amount is about 3.5% without increasing the pressure loss as compared with the radiation fin of the rectangular cross section having the same weight and the same height based on the simulation result described later. It is possible to realize a high improvement effect.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the first portion and the second portion are each a flat plate portion having a substantially constant thickness. According to this structure, unlike the case where at least one of the first portion and the second portion is a curved surface-shaped portion whose thickness changes, it is only necessary to flatten the first portion and the second portion. There is no loss in the processability of the fins.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the radiation fin has a shape in which the first portion and the second portion are connected by one connection portion. According to this structure, the shape of the heat dissipating fins can be simplified as compared to the case where the heat dissipating fins are formed to have cross-sectional shapes that are inclined in multiple steps by a plurality of connecting portions. As a result, even in the configuration in which the thickness of the heat dissipating fin is changed, it is possible to suppress the deterioration of the processability of the heat dissipating fin as much as possible.

  In the heat exchanger for an aircraft engine according to the above invention, preferably, the core portion has a curved shape along a curved surface in the aircraft engine, and a first surface opposite to the curved surface, and a first surface Has a hollow plate shape having an opposite second surface, and the plurality of heat radiation fins are formed on at least one of the first surface and the second surface. According to this structure, in the surface cooler formed along the curved surface (such as the inner circumferential surface of the fan casing) in the aircraft engine, it is possible to meet the weight restriction and the size restriction, and increase the pressure loss. It is possible to improve the amount of heat exchange without

  According to the present invention, as described above, a heat exchanger for an aircraft engine is provided that is adaptable to weight and size limitations and that can improve the amount of heat exchange without increasing the pressure loss. be able to.

It is a typical perspective view showing a heat exchanger by a 1st and 2nd embodiment. FIG. 5 is a schematic cross-sectional view of the heat exchanger taken along line 500-500 in FIG. It is a typical disassembled perspective view for demonstrating the structure of a heat exchanger. It is a figure for demonstrating the shape of the radiation fin of the heat exchanger by 1st Embodiment. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio y / Y of the radiation fin in 1st Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio y / Y of FIG. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio X / x of the radiation fin in 1st Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio X / x of FIG. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio h / Y of the radiation fin in 1st Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio h / Y of FIG. It is a figure for demonstrating the shape of the radiation fin by a comparative example. It is the figure which showed the specific structural example (A)-(D) of the radiation fin in 1st Embodiment. It is a figure for demonstrating the shape of the radiation fin of the heat exchanger by 2nd Embodiment. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio y / Y of the radiation fin in 2nd Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio y / Y of FIG. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio X / x of the radiation fin in 2nd Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio X / x of FIG. It is the calculation result which showed the improvement rate of the heat exchange amount with respect to ratio h / Y of the radiation fin in 2nd Embodiment. It is the calculation result which showed the ratio of the pressure loss with respect to ratio h / Y of FIG. It is the figure which showed the specific structural example (A)-(D) of the radiation fin in 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

  The configuration of the heat exchanger 100 according to the present embodiment will be described with reference to FIGS. 1 to 11. The heat exchanger 100 according to the present embodiment is a heat exchanger for an aircraft engine, and in particular, is an air-cooled heat exchanger (cooler) mounted in the aircraft engine and exchanging heat with the air flow in the aircraft engine. It is provided as An aircraft engine is a type of engine that generates propulsion using air taken in from outside in a cylindrical casing, such as a gas turbine engine, and a high-speed air flow is generated in the casing. The fluid to be cooled is, for example, lubricating oil of an engine, lubricating oil of a generator driven by the engine, or the like.

(Whole structure of heat exchanger)
The entire configuration of the heat exchanger 100 will be described with reference to FIGS. 1 to 3. In the configuration example of FIG. 1, the heat exchanger 100 is configured as a surface cooler. The surface cooler is a heat exchanger of a type that cools the fluid to be cooled that flows inside the core portion 1 by the air flow that flows along the radiation fins 2 provided on the surface of the plate-like core portion 1. In this case, the heat exchanger 100 is formed into a generally curved plate-like shape, and is disposed along the curved surface S (see FIG. 2) in the aircraft engine. The curved surface S in the aircraft engine is, for example, the inner circumferential surface of the fan casing of the engine, but may be installed at any site in the engine as long as it is exposed to the air flow.

  The heat exchanger 100 is typically provided in a length of about 1 / n circumference (n is a natural number) in the circumferential direction (C direction) along the generally cylindrical curved surface S. For example, the heat exchanger 100 is formed to have a length of about 1/8, but the heat exchanger 100 may have an annular shape extending substantially all around the curved surface S in the aircraft engine. Good. The air flows along the A direction (see FIG. 1) which is generally axial (in the rotational axis of the turbine) in the aircraft engine. Since the curved surface S in the aircraft engine does not necessarily have a perfect cylindrical curved surface, the radius of curvature of the heat exchanger 100 in that case differs depending on the position in the axial direction (A direction).

  As shown in FIGS. 1 and 2, the heat exchanger 100 includes a core portion 1 for circulating a fluid to be cooled, and a plurality of plate-like heat radiation fins 2 provided on the surface 10 (see FIG. 2) of the core portion 1. And

  The core portion 1 has a curved shape along the curved surface S in the aircraft engine. The core portion 1 has a hollow plate shape having a first surface 10a opposite to the curved surface S and a second surface 10b opposite to the first surface 10a. A flow path 3 (see FIG. 3) is formed inside the core portion 1. As shown in FIG. 3, the core portion 1 is configured by overlapping the first member 11 on the first surface 10 a side and the second member 12 on the second surface 10 b side in the thickness direction. A flow passage 3 consisting of a recess is formed on the inner surface of the second member 12, and a corrugated fin 31 is disposed in the flow passage 3. By covering the open surface side of the flow path 3 with the first member 11, the flow path 3 for circulating the fluid to be cooled is configured inside the core portion 1.

  The flow path 3 has a folded shape including the forward path 3a and the return path 3b. The outward path 3 a and the return path 3 b are partitioned by the peripheral wall 12 a and the partition portion 12 b formed in the second member 12. The forward path 3a extends from one end to the other end of the core portion 1 in the longitudinal direction (C direction), and the return path 3b extends from the other end of the core portion 1 in the longitudinal direction to one end. The forward path 3 a and the return path 3 b communicate with each other on the other end side of the core portion 1. At one end in the longitudinal direction of the first member 11, a header portion 13 having an inflow port 13a and an outflow port 13b is provided. The inflow port 13 a brings the forward passage 3 a into communication with the outside on one end side of the core portion 1. The outflow port 13 b brings the return path 3 b into communication with the outside on one end side of the core portion 1. Each of the inflow port 13a and the outflow port 13b is connected to a flow path of the fluid to be cooled (not shown).

  The corrugated fins 31 are plate-like fins formed in a wave shape in a direction (flow passage width direction) orthogonal to the extending direction of the flow passage 3 (the forward passage 3a and the return passage 3b). The corrugated fins 31 are respectively joined to the first member 11 and the second member 12 on both sides in the thickness direction, and divide the inside of the flow path 3 into a plurality of fine flow paths.

  The plurality of heat dissipating fins 2 are formed on at least one of the first surface 10 a and the second surface 10 b. In the configuration example of FIGS. 1 to 3, a plurality of heat radiation fins 2 are provided on both the first surface 10 a and the second surface 10 b. The plurality of heat dissipating fins 2 may be provided only on one of the first surface 10 a and the second surface 10 b. Each radiation fin 2 has a plate-like shape. Each radiation fin 2 is provided upright in a direction substantially perpendicular to each surface 10. The plurality of radiation fins 2 are provided in parallel with each other at substantially equal intervals (approximately equal pitches). In FIG. 1, the plurality of heat radiation fins 2 extend along the short side direction (direction A) of the core portion 1. That is, the plurality of heat dissipating fins 2 extend along the axial direction (direction A) in the aircraft engine. The plurality of radiation fins 2 may be inclined with respect to the axial direction (direction A). The plurality of heat radiation fins 2 may not be parallel, and the distance between the fins may not be constant. The structure of each radiation fin 2 will be described later.

  The core portion 1 is made of, for example, aluminum or aluminum alloy, stainless steel, titanium, copper, Inconel (registered trademark) or the like. The material of the radiation fin 2 is also the same as that of the core portion 1. The radiation fin 2 is integrally formed on each of the first member 11 and the second member 12 by processing (such as cutting) on the plate material that constitutes the first member 11 and the second member 12, for example. The core portion 1 is formed, for example, by assembling the first member 11, the second member 12, and the corrugated fins 31 and joining them by brazing or the like. The plurality of heat radiation fins 2 may be formed separately from, for example, the first member 11 and the second member 12 and attached to each of the first member 11 and the second member 12.

  As shown in FIG. 3, the fluid to be cooled flows from the inflow port 13 a of the header portion 13 into the flow path 3 inside the core portion 1. The fluid to be cooled is distributed to the fine flow path portion partitioned by the corrugated fins 31 in the flow path 3 and flows sequentially through the forward path 3a and the return path 3b. On the other hand, outside the core portion 1, a high speed air flow passes along the respective radiation fins 2 on the surface 10 of the core portion 1 as the aircraft engine operates. As a result, heat exchange is performed between the fluid to be cooled flowing inside the core portion 1 (inside the flow path 3) and the air flow from the outside through the core portion 1 and the respective radiation fins 2. That is, the heat of the high-temperature fluid to be cooled is transmitted to the radiation fins 2 through the corrugated fins 31, the first member 11 and the second member 12, and the radiation fins 2 release the air to the outside. The cooled fluid to be cooled flows out of the heat exchanger 100 from the outlet port 13b of the header portion 13, and is returned to the device (engine, generator, etc.) where the fluid to be cooled is used.

First Embodiment
(The radiation fin)
Next, the shape of the radiation fin 2 of the heat exchanger 100 according to the first embodiment will be described. The individual radiation fins 2 of the heat exchanger 100 shown in FIGS. 1 to 3 are formed in the shape as shown in FIG. 4 in detail. FIG. 4 shows the shape of the radiation fin 2 in a cross section orthogonal to the extending direction (direction A) of the radiation fin 2. The lower side of FIG. 4 is the surface 10 side of the core portion 1. Hereinafter, the direction in which the heat dissipating fins 2 protrude from the surface 10 of the core portion 1 (the direction orthogonal to the surface 10) is taken as the height direction of the heat dissipating fins 2. The left and right direction in FIG. 4 is the thickness direction of the radiation fin 2, and the depth direction orthogonal to the height direction and the thickness direction coincides with the A direction. In addition, in FIGS. 1 to 3, for convenience, the respective heat radiation fins 2 are simplified and illustrated as a simple flat plate shape.

  As shown in FIG. 4, the radiation fin 2 includes a first portion 21, a second portion 22, and a connection portion 23. The first portion 21 is a root side portion rising from the surface 10 of the core portion 1. The second portion 22 is a portion of the heat dissipating fin 2 which is disposed closer to the tip than the first portion 21. The second portion 22 has a smaller thickness than the first portion 21. The connecting portion 23 is an inclined portion connecting between the first portion 21 and the second portion 22. In other words, the connection portion 23 is a portion where the thickness changes between the first portion 21 and the second portion 22 having different thicknesses. The connection portion 23 is a portion inclined with respect to the first portion 21 and the second portion 22. The first portion 21, the second portion 22 and the connecting portion 23 are integrally formed.

  The radiation fin 2 has a total height Y (dimension in the height direction) from the surface 10 of the core portion 1. The total height Y is set, for example, in a range of about 10 mm to 50 mm, and is limited within a predetermined value in accordance with the dimensional restriction in the aircraft engine.

  The first portion 21 and the second portion 22 respectively extend along the height direction of the radiation fin 2. Each of the first portion 21 and the second portion 22 has straight side surfaces in the thickness direction. In the first embodiment, each of the first portion 21 and the second portion 22 is a flat portion having a substantially constant thickness (dimension in the thickness direction). That is, the first portion 21 is a flat portion having the thickness X and the length y1 in the height direction, and having the same cross-sectional shape and extending in the depth direction. The first portion 21 is connected to the surface 10 of the core 1 at its lower end. The second portion 22 has a thickness x and a length y2 in the height direction, and is a flat portion having the same cross-sectional shape and extending in the depth direction. The upper end portion of the second portion 22 constitutes the tip of the radiation fin 2. As described above, the relationship of thickness x <thickness X is established. The thickness X of the first portion 21 is equal to the maximum thickness of the radiation fin 2.

  The connecting portion 23 is connected to the first portion 21 at the lower end and to the second portion 22 at the upper end. The connection portion 23 has a height h in the height direction. The connection portion 23 is formed at the position of height y. The height of the formation position of the connection portion 23 is a distance from the surface 10 to the position of the center (h / 2) of the connection portion 23.

  The connection portion 23 has a pair of side surface portions 23a and 23b on both sides in the thickness direction. The connection portion 23 has at least one inclined side portion. That is, as shown in FIG. 4, the side portions 23a and 23b are inclined on both sides, or one side is inclined (see FIG. 13). In addition, in this specification, that the connection part 23 or side part 23a, 23b inclines means that it inclines with respect to the 1st part 21 and the 2nd part 22. As shown in FIG. Further, the connection portion 23 is inclined with respect to the height direction of the radiation fin 2. The inclined side surface portion does not include a shape in which the side surface portion is parallel to the height direction of the heat dissipation fin 2 and a shape in which the side surface portion is perpendicular to the height direction of the heat dissipation fin 2 (parallel to the thickness direction).

  The thickness of the connection portion 23 changes between the thickness X of the first portion 21 and the thickness x of the second portion 22 due to the inclined side portions 23a and 23b. In the example of FIG. 4, the maximum thickness of the connection portion 23 is equal to the thickness X, and the minimum thickness of the connection portion 23 is equal to the thickness x. The side surface portions 23 a and 23 b are inclined such that the thickness of the connection portion 23 decreases toward the second portion 22. The side portions 23a and 23b are formed as linear inclined surfaces. That is, the inclination angle θ of the side portions 23 a and 23 b is substantially constant throughout the connection portion 23. The term “substantially constant” means that the inclination angle of the upper end and the lower end is changed or the inclination angle is allowed to vary due to processing restrictions of the radiation fin 2 or dimensional error. In the example of FIG. 4, the inclination angles θ of the side portions 23a and 23b are substantially the same.

  The radiation fin 2 has a shape in which one first portion 21 and one second portion 22 are connected by one connection portion 23. That is, the radiation fin 2 is configured by three parts of one first part 21, one second part 22, and one connection part 23. The radiation fin 2 is formed in a shape in which the thickness is reduced at an intermediate position (connection portion 23) in the height direction.

  In the first embodiment, the side surfaces 23a and 23b of the connecting portion 23 are formed on the side surfaces 20a and 20b, respectively. In the example of FIG. 4, inclined side portions 23 a and 23 b are respectively formed on both the side surface 20 a on the left side (one side) in the drawing and the side surface 20 b on the right side (the other side) in the drawing.

  The radiation fin 2 has a symmetrical shape. The centers in the thickness direction of the first portion 21, the second portion 22, and the connection portion 23 coincide with each other. The side surface 20a on one side of the radiation fin 2 and the side surface 20b on the other side have a symmetrical shape with the center in the thickness direction being interposed.

(Dimension relationship of radiation fin)
Next, the relationship of the dimensions of each part of the radiation fin 2 will be described. In the first embodiment, the radiation fin 2 has a height y of the formation position of the connection portion 23 in the radiation fin 2, a thickness X of the first portion 21, a thickness x of the second portion 22, a length h of the connection portion 23, etc. Are formed to satisfy a predetermined relationship.

  FIGS. 5-10 is a calculation result of the simulation based on Computational fluid dynamics (computational fluid dynamics) which computed the improvement rate (increase rate) of heat exchange amount by making each dimension of the radiation fin 2 into a variable parameter. The predetermined relationship which the shape of the radiation fin 2 of the first embodiment should satisfy is derived based on the calculation result of this simulation. Hereinafter, the shape of the radiation fin 2 will be described together with the calculation result.

In the simulation, the air flow was assumed to be a three-dimensional steady, compressible flow, and calculated using a k- [epsilon] turbulence model. As the simulation conditions, the flow velocity on the air side = 100 [m / s], the temperature = 40 [° C.], and 1 atm, and the temperature on the high temperature side (the surface 10 of the core portion 1) = 150 [° C.]. The radiation fins 2 were set to have a density (2702.0 [kg / m ³ ]) and a thermal conductivity (237.0 [W / (m · K)]) on the assumption that they were made of aluminum.

  In the simulation, the comparative example shown in FIG. 11 is used as a reference (improvement rate = 1) as an index of the improvement rate of the heat exchange amount. The comparative example is a flat heat radiation fin CF having a rectangular cross section formed so that the root side and the tip side have the same thickness Xc.

  About total height Y of radiation fin 2 (CF) of a comparative example and a 1st embodiment, three patterns of Y = 10 [mm], 20 [mm], and 30 [mm] (except FIG. 9 and FIG. 10) Calculations were made for In the radiation fin 2 (CF) of the comparative example and the first embodiment, the length in the depth direction (flow direction) is 150 [mm], and the cross-sectional shape is constant over the entire length in the depth direction (see FIGS. 4 and 11). did. The thickness Xc of the radiation fin CF of the comparative example was set such that the weight of the radiation fin CF and the weight of the radiation fin 2 of the first embodiment coincide. Here, since it is assumed that the radiation fins 2 and the radiation fins CF have a constant cross-sectional shape and the lengths in the depth direction are equal, equal weights mean that the cross-sectional areas are equal.

  The calculation is as follows: (point 1) height y of the formation position of the connecting portion 23, (point 2) thickness x of the second portion 22, (point 3) length h of the connecting portion 23 in the height direction The formation range of 23) was performed about three viewpoints.

  (Viewpoint 1) The height y (see FIG. 4) of the formation position of the connection portion 23 corresponds to the total height Y of the radiation fin 2 from the surface 10 of the core portion 1 from the surface 10 of the core portion 1 to the connection portion 23 It can be generalized as the ratio y / Y of the height y to the formation position. As the ratio y / Y is smaller, the connection portion 23 is disposed on the root side of the radiation fin 2, and as the ratio y / Y is larger, the connection portion 23 is disposed on the tip side of the radiation fin 2. The first portion 21 is not formed when y / Y = 0 (y = 0), and the second portion 22 is not formed when y / Y = 1 (y = Y). It is 0 <y / Y <1 as a range which can be taken in calculation.

  (Aspect 2) The thickness x of the second portion 22 can be generalized as a ratio X / x of the thickness X of the first portion 21 to the thickness x of the second portion 22. When the value of the ratio X / x is 1, the same rectangular cross section as the comparative example is obtained, and when the value of the ratio X / x is larger than 1, the second portion 22 on the tip side is narrowed. The smaller the ratio X / x, the smaller the aperture (difference in thickness between the second portion 22 and the first portion 21) at the tip end of the radiation fin 2, and the larger the ratio X / x, the tip side of the radiation fin 2 As the aperture increases, the second portion 22 becomes relatively thinner. In the first embodiment, since x <X, the ratio X / x can be set as 1 <X / x as a calculationally possible range.

  (Viewpoint 3) The length h of the connection portion 23 in the height direction is the length h of the connection portion 23 in the height direction of the radiation fin 2 with respect to the total height Y of the radiation fin 2 from the surface 10 of the core portion 1 It can be generalized as the ratio h / Y of As the value of the ratio h / Y decreases, the inclination angle θ of the connection portion 23 increases, and the connection portion 23 approaches a step shape with a right angle. As the value of the ratio h / Y increases, the inclination angle θ of the connection portion 23 decreases, and the radiation fin 2 approaches a flat plate shape. In the first embodiment, h / Y> 0 because the connecting portion 23 is inclined, and when h / Y = 1, the first portion 21 and the second portion 22 are not formed, so the ratio h / Y is calculated The range that can be taken is 0 <h / Y <1.

  In the calculation, one of the ratio y / Y of (viewpoint 1), the ratio X / x of (viewpoint 2), and the ratio h / Y of (viewpoint 3) is taken as a variable parameter, and the other parameters are taken as fixed parameters. Calculation was done for each viewpoint.

<Formation position of connection part>
The ratio y / Y (viewpoint 1) of the height y of the formation position of the connection portion 23 to the total height Y will be described. FIG. 5 shows the change in the rate of improvement of the amount of heat exchange relative to the comparative example (rate of improvement = 1) when the ratio y / Y is varied, and FIG. 6 shows the case where the ratio y / Y is varied, The change of the ratio of the pressure loss with respect to a comparative example (ratio = 1) is shown. In each figure, a plurality of calculation results were plotted to obtain an approximate curve. FIG. 5 and FIG. 6 use the ratio y / Y as a variable parameter, and set the ratio X / x = 2.2 and the ratio h / Y = 0 as fixed parameters. The ratio h / Y = 0 represents the case where the connection portion 23 has a step shape with a right angle (tilt angle θ = 90 degrees), and is set for convenience of evaluation of variable parameters.

  Based on the calculation results of FIG. 5 and FIG. 6, in the first embodiment, the heat dissipating fins 2 are connected from the surface 10 of the core portion 1 to the total height Y of the heat dissipating fins 2 from the surface 10 of the core portion 1. The ratio y / Y of the height y to the formation position of is so formed as to satisfy the relationship 0.34 <y / Y <0.64.

  Specifically, in FIG. 5, the improvement rate becomes maximum around ratio y / Y = 0.5 as a tendency common to each of the total height Y, and it is about 3.5% to about 4.8. The improvement rate is about%. The rate of improvement gradually decreases with the ratio y / Y = 0.5. An improvement rate of about 2% (about 1.8%) or more is obtained in the range of 0.34 <y / Y <0.64. In FIG. 6, when the ratio y / Y = 0.34, although the pressure loss exceeds the comparative example (= 1.00) at Y = 20 mm, it falls sharply in the range of 0.34 <y / Y. It turns out that it is less than a comparative example. At Y = 10 mm and 30 mm, the pressure drop is consistently below the comparative example. Therefore, by setting the ratio y / Y to 0.34 <y / Y <0.64, an improvement rate of about 2% or more can be expected without the pressure loss exceeding that of the comparative example.

  In addition, since the height y to the formation position of the connection portion 23 is based on the center (h / 2) in the height direction of the connection portion 23, for example, the ratio y / Y has a value near the upper limit or the lower limit of the above range. In this case, the lower end of the connection portion 23 may be disposed at a position lower than 34% of the total height Y, or the upper end of the connection portion 23 is more than 64% of the total height Y It may be arranged at a high position.

  Also preferably, the ratio y / Y satisfies the relationship of 0.42 <y / Y <0.64. In this case, at any total height Y, the pressure loss is lower than the comparative example, and an improvement rate of about 3% or more can be expected with respect to the heat exchange amount with respect to the comparative example. More preferably, the ratio y / Y satisfies the relationship of 0.45 <y / Y <0.59. In this case, at any total height Y, an improvement rate near the peak can be achieved with respect to the heat exchange amount. In particular, at Y = 20 mm and Y = 30 mm, an improvement rate of 4% or more can be expected.

<Thickness of second part>
The ratio X / x of the thickness X of the first portion 21 to the thickness x of the second portion 22 (viewpoint 2) will be described. In FIG. 7 and FIG. 8, the ratio of heat exchange is improved when the ratio x / x is a variable parameter and the ratio y / Y = 0.5 and the ratio h / Y = 0 are set as fixed parameters (FIG. 7) And the ratio of pressure drop to the comparative example (FIG. 8). In FIGS. 7 and 8, the comparative example (see FIG. 11) corresponds to the ratio X / x = 1.

  Based on the calculation results of FIG. 7 and FIG. 8, the radiation fin 2 has a ratio X / x of the thickness X of the first portion 21 to the thickness x of the second portion 22 of 1.0 <X / x <5.4. It is preferable that it is formed to satisfy the relationship.

  In FIG. 7, the improvement rate is maximum around the ratio X / x = 2.2 (about 3.5% to about 4.8%) as a tendency common to each of the total heights Y. Then, the improvement rate tends to decrease as the distance from the ratio X / x = 2.2 to both sides. The improvement rate is 0% at the ratio X / x = 1, and the improvement rate exceeds the comparative example in the range of 1.0 <X / x <5.4. In the pressure loss ratio of FIG. 8, the pressure loss monotonously decreases as the ratio X / x increases from X / x = 1.0. Therefore, when the ratio X / x is set in the range of 1.0 <X / x <5.4, an improvement in the amount of heat exchange can be expected without increasing the pressure loss in the comparative example.

  Here, as the heat exchanger 100 for an aircraft engine, generally, the maximum thickness X of the radiation fin 2 is approximately less than 3 mm, and may be less than 2 mm or about 1 mm. For this reason, when the ratio X / x exceeds 5.4, the thickness x of the second portion 22 becomes too small, and the processability (easiness of processability) may be reduced. Therefore, in the case where the ratio X / x is 1.0 <X / x <5.4, the processability can be secured while improving the heat exchange amount with respect to the comparative example.

  Also, more preferably, the ratio X / x satisfies the relationship of 1.5 <X / x <4.5. In the range of 1.5 <X / x <4.5, it can be seen that the improvement rate is approximately 2% or more at any total height Y. And pressure loss is also less than a comparative example. Therefore, by setting the ratio X / x to 1.5 <X / x <4.5, an improvement rate of about 2% or more over the comparative example is expected in heat exchange amount without increasing the pressure loss. it can.

  More preferably, the ratio X / x satisfies the relationship 2.0 <X / x <4.2. In this case, even when focusing on Y = 10 mm, which is the smallest improvement rate, an improvement rate of about 3% or more can be expected relative to the comparative example. Therefore, by setting the ratio X / x to 2.0 <X / x <4.2, an improvement rate of about 3% or more over the comparative example is expected in heat exchange amount without increasing the pressure loss. it can.

<Length of connected part>
The ratio h / Y (viewpoint 3) of the length h of the connection portion 23 to the total height Y of the radiation fin 2 will be described. 9 and 10, when the ratio h / Y is a variable parameter, and the ratio y / Y = 0.5 and the ratio X / x = 2.2 are set as fixed parameters, the improvement rate of the amount of heat exchange (figure 9) shows the pressure drop ratio (FIG. 10) for the comparative example. For this calculation, the total height Y of the heat radiation fins 2 was 20 mm.

  Based on the calculation results of FIG. 9 and FIG. 10, in the first embodiment, the radiation fin 2 is a connection portion in the height direction of the radiation fin 2 with respect to the total height Y of the radiation fin 2 from the surface 10 of the core portion 1 It is preferable that the ratio h / Y of the length h of 23 be formed to satisfy the relationship of 0 <h / Y <0.64.

  In FIG. 9, the improvement rate is substantially constant (about 3.5%) near the maximum value in the range of 0 <h / Y <0.50. And although it is gentle, the improvement rate monotonously decreases as it increases from the ratio h / Y = 0.4. Even at the ratio h / Y = 0.64, the improvement rate exceeds 3%. In FIG. 10, as the ratio h / Y = 0 increases, the pressure loss monotonously increases, but in each case, the value is lower than that of the comparative example (= 1.00). Therefore, by setting the ratio h / Y in the range of 0 <h / Y <0.64, an improvement rate of about 3% or more over the comparative example is expected in heat exchange amount without increasing the pressure loss. it can.

  More preferably, the ratio h / Y satisfies the relationship of 0 <h / Y <0.40. In this case, an improvement rate of about 3.5% near the maximum value can be expected for the comparative example. More preferably, the ratio h / Y satisfies the relationship 0 <h / Y <0.20. In FIG. 10, in the range of 0 <h / Y <0.20, the rising tendency of the pressure loss is gradual and can be regarded as almost constant. When h / Y exceeds 0.20, the slope of the pressure drop along with the increase in the ratio h / Y becomes large. Therefore, by setting the ratio h / Y in the range of 0 <h / Y <0.20, an improvement ratio of about 3.5% or more can be expected with respect to the comparative example, and the pressure loss is effectively reduced. can do.

<About calculation results>
If the dimensions in the air flow direction (depth direction, A direction) are the same, the weight of the heat dissipating fins 2 is determined by the cross-sectional area. Since the above calculation was performed under the same height and cross-sectional area as the comparative example of FIG. 11, the height dimension and weight of the radiation fin 2 of the first embodiment are not changed in comparison with the comparative example. . Therefore, it can be understood from the calculation results of FIG. 5 to FIG. 10 that the heat exchange amount can be improved while the heat dissipating fins 2 of the first embodiment are adapted to the weight restriction and the size restriction. Further, it can be understood from the calculation results of the pressure loss in FIGS. 6, 8 and 10 that the pressure loss can be further reduced.

<Example of configuration of heat radiation fin>
12A to 12D are specific examples of the shape of the radiation fin 2 included in each parameter range obtained from the above calculation results. The radiation fin 2a of FIG. 12A is formed to satisfy the relationship of ratio y / Y = 0.50, ratio X / x = 2.2, and ratio h / Y = 0.10. The radiation fin 2b of FIG. 12B is formed to satisfy the relationship of ratio y / Y = 0.43, ratio X / x = 1.6, and ratio h / Y = 0.20. The radiation fin 2c in FIG. 12C is formed to satisfy the relationship of ratio y / Y = 0.35, ratio X / x = 5.3, and ratio h / Y = 0.40. The radiation fin 2d of FIG. 12D is formed to satisfy the relationship of ratio y / Y = 0.63, ratio X / x = 4.4, and ratio h / Y = 0.63. Thus, the heat dissipating fins 2 in the heat exchanger 100 of the first embodiment include various modifications included in the above parameter range for each parameter of the ratio y / Y, the ratio X / x, and the ratio h / Y. sell.

(Effect of the first embodiment)
In the first embodiment, the following effects can be obtained.

  In the first embodiment, the radiation fin 2 is formed such that the ratio y / Y satisfies the relationship of 0.34 <y / Y <0.64 based on the above simulation result (see FIGS. 5 and 6). Therefore, it is possible to realize the improvement effect of the heat exchange amount of about 2% or more (about 1.8% or more) as compared with the radiation fin CF (refer to FIG. 11) of the rectangular cross section with the same weight and the same height. It becomes. As a result, the heat exchange amount can be improved (increased) while being compatible with weight restrictions and size restrictions, and without increasing pressure loss.

  Further, based on the above simulation results (see FIGS. 7 and 8), when forming the radiation fin 2 so that the ratio X / x satisfies the relationship of 1.0 <X / x <5.4, the same weight -It becomes possible to aim at improvement of the amount of heat exchange, without making pressure loss increase compared with radiation fin CF (refer to Drawing 11) of the rectangular section of the same height. In addition, when the thickness ratio (X / x) is in the range of 1.0 <X / x <5.4, the difference in thickness between the second portion 22 and the first portion 21 may be too large (or too small). Since the heat dissipating fins 2 are actually formed, the processability (easiness of processing) of the heat dissipating fins 2 can be secured.

  Further, based on the above simulation results (see FIGS. 9 and 10), when forming the radiation fin 2 so that the ratio h / Y satisfies the relationship of 0 <h / Y <0.64, the same weight and the same weight It is possible to realize the improvement effect of the heat exchange amount of at least 3% or more as compared with the radiation fin CF (refer to FIG. 11) of the rectangular cross section of the height.

  In addition, since the first portion 21 and the second portion 22 are flat portions each having a substantially constant thickness, at least one of the first portion 21 and the second portion 22 is a curved portion in which the thickness changes. Unlike the above, since the first portion 21 and the second portion 22 need only be flat, the processability of the radiation fin 2 is not impaired.

  Further, since the heat dissipating fins 2 have a shape in which the first portion 21 and the second portion 22 are connected by one connecting portion 23, the plurality of connecting portions 23 form a heat dissipating fin having a cross-sectional shape inclined in multiple steps. The shape of the radiation fin 2 can be simplified as compared with the case where it is carried out. As a result, even in the configuration in which the thickness of the heat dissipating fins 2 is changed, it is possible to suppress the deterioration of the processability of the heat dissipating fins 2 as much as possible.

  In addition, since a plurality of heat radiation fins 2 are formed on at least one of the first surface 10a and the second surface 10b of the core portion 1 having a curved shape along the curved surface S, it is formed along the curved surface S in the aircraft engine In the surface cooler, it is possible to meet weight and size limitations and to improve the amount of heat exchange without increasing the pressure loss.

  Further, since the inclined side portions 23a and 23b of the connection portion 23 are provided on both side surfaces 20a and 20b of the heat dissipating fin 2, the heat is dissipated in which the inclined side portions 23a and 23b are formed on one side and the other side. Since the fins 2 can be obtained, no significant difference occurs in the heat exchange performance, regardless of which side of the radiation fin faces the air flow swirling in the aircraft engine. That is, the air flow in the aircraft engine is mainly directed in the A direction, but a flow occurs that swirls along the inner circumferential surface of the fan casing. Therefore, if the shapes of both side surfaces 20a and 20b differ significantly, the air flow It is necessary to consider which side of the heat dissipating fin is directed to the turning direction. Therefore, in the first embodiment, since the influence of the direction of the heat radiation fins 2 on the direction of the air flow in the aircraft engine can be suppressed, the heat exchanger can be easily designed. In particular, in the case where the inclination angles θ of the side portions 23a and 23b are matched to make the radiation fins 2 symmetrical, the same heat exchange performance is obtained regardless of which of the side surfaces 20a and 20b faces the direction of the air flow. You can get

  Also, based on the simulation results (see FIGS. 9 and 10), when forming the radiation fin 2 so that the ratio h / Y satisfies the relationship of 0 <h / Y <0.40, the same weight and the same height Compared to the radiation fin CF (see FIG. 11) having a rectangular cross section, it is possible to realize a high improvement effect of about 3.5% in the amount of heat exchange without increasing the pressure loss.

Second Embodiment
A second embodiment will be described with reference to FIGS. 13 to 20. The heat exchanger 200 (see FIGS. 1 to 3) according to the second embodiment is different from the first embodiment in which the inclined side portions 23a and 23b of the connection portion 23 are formed on both side surfaces of the radiation fin 2, respectively. An example in which the side surface 120a on one side of the radiation fin 102 is a flat surface, and the inclined side surface portion 123b of the connection portion 123 is formed on the other side surface 120b will be described. In the second embodiment, the configuration other than the shape of the heat dissipating fins 102 is the same as that of the first embodiment, so the same reference numerals will be used and the description will be omitted.

(The radiation fin)
As shown in FIG. 13, the radiation fin 102 of the second embodiment includes a first portion 121, a second portion 122, and a connection portion 123. The radiation fin 102 has a shape in which one first portion 121 and one second portion 122 are connected by one connection portion 123. The first portion 121 and the second portion 122 are flat portions each having a substantially constant thickness.

  Also in the second embodiment, the same reference numerals as those in the second embodiment are used for the dimensions of each part of the heat dissipating fins 102. That is, in the following description, the total height Y of the radiation fin 102 from the surface 10 of the core portion 1, the thickness X of the first portion 121, the thickness x of the second portion 122, and the length in the height direction of the connecting portion 123 Use h.

  In the second embodiment, the side surface 120a on one side of the heat dissipating fin 102 is a flat surface, and the inclined side surface portion 123b of the connection portion 123 is formed on the side surface 120b on the other side. In the example of FIG. 13, the side surface 120a on the left side (one side) in the drawing is formed to be a flat surface substantially parallel to the height direction. An inclined side surface portion 123b is formed on the side surface 120b on the right side (the other side) in the drawing.

  The side surface 120 a on one side is a flat surface rising linearly from the surface 10 by forming the side surfaces of the first portion 121, the second portion 122, and the connection portion 123 in the same plane. Therefore, in the thickness direction, the positions of the side surface portions on one side of each of the first portion 121, the second portion 122, and the connection portion 123 coincide with each other.

  On the other side 120b, the side portions of the first portion 121, the second portion 122, and the connecting portion 123 are formed at different positions in the thickness direction. The side surface of the other side of the first portion 121 is disposed at a distance X from the side surface 120a, and the side surface of the other side of the second portion 122 is disposed at a distance x from the side surface 120a. The inclined side surface portion 123b of the connection portion 123 is inclined so that the thickness decreases toward the second portion 122 by the difference between the thickness X of the first portion 121 and the thickness x of the second portion 122.

  As described above, in the second embodiment, since the radiation fin 102 is provided with the side surface portion 123b inclined only on the other side, it is not symmetrical in the left-right direction, but has a shape that is biased to one side as a whole. The heat dissipating fins 102 may be shaped to be symmetrical to the shape shown in FIG. 13 in the thickness direction. That is, the inclined side surface portion 123b may be provided on the side surface 120a on one side of the heat radiation fin 102, and the side surface 120b on the other side may be a flat surface.

(Dimension relationship of radiation fin)
Next, the relationship of the dimensions of each part of the radiation fin 102 will be described.

  FIG. 14 to FIG. 19 show the calculation results of the simulation in which the improvement rate (increase rate) of the heat exchange amount is calculated with each dimension of the heat radiation fin 102 as a variable parameter. The calculation conditions of the simulation in the second embodiment are the same as those in the first embodiment. In the first embodiment, the total height Y of the radiation fins 102 (CF) is comprehensively calculated with three patterns of Y = 10 [mm], 20 [mm], and 30 [mm], In the second embodiment, calculation was performed for Y = 20 [mm] as a representative value of the total height Y, and the improvement rate of the heat exchange amount and the pressure loss were evaluated. Also in the second embodiment, simulations were performed with the ratio y / Y, the ratio X / x, and the ratio h / Y as variable parameters.

<Formation position of connection part>
The ratio y / Y (viewpoint 1) of the height y of the formation position of the connection portion 123 to the total height Y will be described. In FIG. 14 and FIG. 15, the ratio y / Y is a variable parameter, and the ratio X / x = 2.2 and the ratio h / Y = 0 are set as fixed parameters.

  Based on the calculation results of FIG. 14 and FIG. 15, in the second embodiment, as in the first embodiment, the radiation fin 102 corresponds to the core portion 1 with respect to the total height Y of the radiation fin 102 from the surface 10 of the core portion 1. The ratio y / Y of the height y from the surface 10 to the formation position of the connection portion 123 is formed to satisfy the relationship of 0.34 <y / Y <0.64.

  Specifically, in FIG. 14, the improvement ratio is about 1.8% to about 3.4% in the range of 0.34 <y / Y <0.64, and the ratio y / Y = 0 The improvement rate is maximum (about 3.4%) around .57. On the other hand, in the pressure loss ratio of FIG. 15, the pressure loss becomes minimum (about 0.985) near the ratio y / Y = 0.44 as the ratio y / Y increases, and then gradually increases and the ratio y It turns out that it becomes equivalent (about 1) to a comparative example by /Y=0.64, and if ratio y / Y exceeds 0.64, pressure loss will increase rather than a comparative example. Therefore, by setting the ratio y / Y to 0.34 <y / Y <0.64, the improvement of the heat exchange amount of about 1.8% or more is achieved without increasing the pressure loss relative to the comparative example. I can expect it.

  Also preferably, the ratio y / Y satisfies the relationship of 0.42 <y / Y <0.64. In this case, an improvement of about 3% or more in the amount of heat exchange can be expected without increasing the pressure loss as compared with the comparative example.

<Thickness of second part>
Next, the ratio X / x of the thickness X of the first portion 121 to the thickness x of the second portion 122 (viewpoint 2) will be described. FIG. 16 and FIG. 17 have the ratio X / x as a variable parameter, and the improvement rate of the heat exchange amount when the ratio y / Y = 0.5 and the ratio h / Y = 0 are set as fixed parameters (FIG. 16) And the ratio of pressure drop to the comparative example (FIG. 17).

  Based on the calculation results of FIG. 16 and FIG. 17, in the second embodiment, the radiation fin 102 has a ratio X / x of the thickness X of the first portion 121 to the thickness x of the second portion 122 as in the first embodiment. Preferably, they are formed to satisfy the relationship of 1.0 <X / x <5.4.

  In FIG. 16, the improvement rate is maximum around the ratio X / x = 2.2 (about 3.4%). Then, the improvement rate tends to decrease as the distance from the ratio X / x = 2.2 to both sides. The improvement ratio is approximately 0% at the ratio X / x = 1 and the ratio X / x = 5.4, and the improvement ratio exceeds the comparative example in the range of 1.0 <X / x <5.4. Recognize. In the pressure loss ratio of FIG. 17, the pressure loss monotonously decreases as the ratio X / x increases from X / x = 1.0. Therefore, when the ratio X / x is set in the range of 1.0 <X / x <5.4, an improvement in the amount of heat exchange can be expected without increasing the pressure loss in the comparative example.

  Also, more preferably, the ratio X / x satisfies the relationship of 1.3 <X / x <3.8. In this case, an improvement of about 2% or more in the amount of heat exchange can be expected without increasing the pressure loss with respect to the comparative example. More preferably, the ratio X / x satisfies the relationship of 1.7 <X / x <2.8. In this case, an improvement of about 3% or more in the amount of heat exchange can be expected without increasing the pressure loss as compared with the comparative example.

<Length of connected part>
Next, the ratio h / Y (viewpoint 3) of the length h of the connection portion 123 to the total height Y of the radiation fin 102 will be described. 18 and 19 show the improvement rate of the amount of heat exchange when the ratio h / Y is a variable parameter and the ratio y / Y = 0.5 and the ratio X / x = 2.2 are set as fixed parameters (Figure 18) and the pressure drop ratio for the comparative example (FIG. 19).

  Based on the calculation results of FIG. 18, in the second embodiment, as in the first embodiment, the radiation fin 102 is the height of the radiation fin 102 with respect to the total height Y of the radiation fin 102 from the surface 10 of the core portion 1. It is preferable that the ratio h / Y of the length h of the connection portion 123 in the direction is formed to satisfy the relationship of 0 <h / Y <0.64.

  In FIG. 18, the improvement rate is maximum around a ratio h / Y = 0.32 (about 3.8%). The improvement rate monotonously decreases as the ratio h / Y = 0.32. It can be seen that the improvement rate of the heat exchange amount of 3.3% or more can be obtained when the ratio h / Y is in the range of 0 <h / Y <0.64. In the ratio of pressure loss shown in FIG. 19, the decrease peak (about 0.99) is obtained when the ratio h / Y is about 0.2, and the pressure loss falls within the range of 0 <h / Y <0.64. Is below the comparative example (= 1.00). Therefore, by setting the ratio h / Y to 0 <h / Y <0.64, an improvement of about 3.3% or more in the amount of heat exchange can be expected without increasing the pressure loss in the comparative example. .

  Furthermore, more preferably, the ratio h / Y satisfies the relationship of 0.20 <h / Y <0.50. In this case, an improvement of about 3.7% or more in the amount of heat exchange can be expected without increasing the pressure loss with respect to the comparative example.

<Example of configuration of heat radiation fin>
FIGS. 20A to 20D are specific examples of the shape of the radiation fin 102 included in each parameter range obtained from the above calculation results. The radiation fin 102a of FIG. 20A is formed to satisfy the relationship of ratio y / Y = 0.57, ratio X / x = 2.2, and ratio h / Y = 0.32. The radiation fin 102b of FIG. 20B is formed to satisfy the relationship of ratio y / Y = 0.35, ratio X / x = 1.3, and ratio h / Y = 0.10. The radiation fin 102c in FIG. 20C is formed to satisfy the relationship of ratio y / Y = 0.63, ratio X / x = 5.3, and ratio h / Y = 0.30. The radiation fin 102d of FIG. 20D is formed to satisfy the relationship of ratio y / Y = 0.42, ratio X / x = 3.8, and ratio h / Y = 0.63. Thus, the heat dissipating fins 102 in the heat exchanger 200 of the second embodiment include various modifications included in the above parameter range for each parameter of the ratio y / Y, the ratio X / x, and the ratio h / Y. sell.

(Effect of the second embodiment)
In the second embodiment, the following effects can be obtained.

  In the second embodiment, based on the above simulation results (see FIGS. 14 and 15), the ratio y / Y satisfies the relationship 0.34 <y / Y <0.64, as in the first embodiment. Since the heat dissipating fins 102 are formed to satisfy the conditions, the heat exchange amount is approximately 2% or more (approximately 1.8% or more) as compared with the heat dissipating fins CF (see FIG. 11) of rectangular cross section having the same weight and height. It is possible to realize the improvement effect of As a result, the heat exchange amount can be improved (increased) while being compatible with weight restrictions and size restrictions, and without increasing pressure loss.

  Further, based on the above simulation results (see FIGS. 18 and 19), when forming the radiation fin 2 so that the ratio h / Y satisfies the relationship of 0.20 <h / Y <0.50, the same weight・ High improvement near peak of about 3.7% to about 3.8% in amount of heat exchange, without increasing pressure loss, compared to radiation fins CF (see FIG. 11) of rectangular cross section at the same height It becomes possible to realize the effect.

  Further, in the second embodiment, since the side surface 120a on one side of the radiation fin 102 is a flat surface, and the inclined side surface portion 123b of the connection portion 123 is formed on the side surface 120b on the other side, the side surface on one side of the radiation fin 102 The flat portion 120a can be formed as a simple flat surface similar to the general rectangular cross-section heat dissipating fins CF. Then, on the other side surface 120 b of the heat dissipating fin 102, the inclined side surface portion 123 b can be formed to make the first portion 121 and the second portion 122 different in thickness. Further, for example, skive processing can be adopted, so that the easiness of processing can be improved, and the freedom of selection of the processing method can be secured.

[Modification]
It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the description of the embodiments described above but by the claims, and further includes all modifications (modifications) within the meaning and scope equivalent to the claims.

  For example, although the example of the heat exchanger which is a surface cooler was shown in the said, 1st and 2nd embodiment, this invention is not limited to this. The present invention may be a heat exchanger provided for an aircraft engine, and may be applied to a plate fin type heat exchanger other than a surface cooler or a shell and tube type heat exchanger. In that case, it is not necessary to provide a heat exchanger along the curved surface S in the aircraft engine, the heat exchanger may be installed at a predetermined position in the engine, or part of the air flow in the engine is branched A heat exchanger may be installed in a bypass flow path or the like that flows.

  Further, in the first and second embodiments, although an example in which the lubricating oil of the engine or the lubricating oil of the generator is used as the fluid to be cooled is shown, the present invention is not limited to this. The type of fluid to be cooled is not particularly limited. The fluid to be cooled may be any fluid.

  In the first and second embodiments, each of the plurality of radiation fins 2 (102) provided on the surface 10 of the core portion 1 is formed into a predetermined shape as shown in FIG. 4 (FIG. 13). However, the present invention is not limited to this. In the present invention, it is not necessary for all the heat dissipating fins to be formed in the same shape, and some of the heat dissipating fins may have the same shape as the heat dissipating fins CF according to the comparative example of FIG. Moreover, the parameters (ratio y / Y, ratio X / x, ratio h / Y) regarding the shape of the radiation fin do not have to be constant values, and the above-mentioned parameters are different for each one or a plurality of radiation fins. May be

  Further, for example, in FIG. 5, an example using values of X / x = 2.2 and h / Y = 0 for each fixed parameter (ratio X / x, ratio h / Y) other than the ratio y / Y is used. Although shown, the present invention is not limited to this. In the present invention, at least the ratio y / Y should satisfy the relationship of 0.34 <y / Y <0.64, and the ratio X / x and the ratio h / Y have any values. Good. Therefore, if the ratio y / Y satisfies the relationship 0.34 <y / Y <0.64, the ratio X / x does not satisfy 1.0 <X / x <5.4. The ratio h / Y may be a value that does not satisfy 0.0 <h / Y <0.64.

  That is, since the thickness x of the second portion 22 is smaller than the thickness X of the first portion 21, the ratio X / x can be 1 <X / x as a structurally possible range. The upper limit of the possible range of X / x depends on the limit of practical processing accuracy and the limit of strength of the second portion 22. Therefore, if the ratio y / Y satisfies the relationship of 0.34 <y / Y <0.64, the ratio X / x may be a value in the range of 5.4 ≦ X / x.

  In addition, since the first portion 21 and the second portion 22 are not formed when the ratio h / Y = 1 (h = Y), h / Y is less than 1 as a structurally possible range of the ratio h / Y. . Therefore, if the ratio y / Y satisfies the relationship of 0.34 <y / Y <0.64, the ratio h / Y may have a value in the range of 0.64 <h / Y <1. .

  Further, in the first and second embodiments, in the radiation fin 2 (102), one first portion 21 (121) and one second portion 22 (122) are connected by one connection portion 23 (123). Although the configuration example having the connected shape is shown, the present invention is not limited to this. In the present invention, the third portion, the fourth portion,. . . The heat dissipating fins may be formed to have a shape in which the thickness can be narrowed in a plurality of steps by further providing. For example, if the first to third parts are connected by two connection parts, the radiation fin has a shape in which the thickness can be reduced in two steps, and if the first to fourth parts are connected by three connection parts The fin has a shape that can be reduced in thickness in three steps. In that case, the height y of the formation position of each connection portion may satisfy the relationship of 0.34 <y / Y <0.64.

  In the first and second embodiments, the first portion 21 (121) and the second portion 22 (122) both have flat plate-like portions whose thicknesses (X and x) are substantially constant. However, the present invention is not limited to this. In the present invention, the thickness of the first portion and the second portion may not be constant. For example, the first portion and the second portion may be tapered plate-like portions whose thickness decreases toward the distal end. In this case, the inclination angles of the side surface portions of the connection portion may be different from the inclination angles of the side surface portions of the first portion and the second portion.

  Moreover, although the example which formed the radiation fin 2 (102) in the shape extended in a depth direction by the same cross-sectional shape was shown in the said, 1st and 2nd embodiment, this invention is not limited to this. In the present invention, the shape (the size of the first portion and the second portion, the position and the range of the connection portion) at each position in the depth direction of the heat dissipation fin is not particularly limited. That is, the heat dissipating fins (the first portion, the second portion, and the connecting portion) may be configured to have different cross-sectional shapes depending on the position in the depth direction. Even in that case, in the cross section at any position in the depth direction, the ratio y / Y may satisfy the relationship of 0.34 <y / Y <0.64.

  Therefore, for example, the radiation fin 2 may be formed such that the height y of the formation position of the connection portion 23 changes from the upstream side to the downstream side in the depth direction (the air flow direction). That is, the height y may be larger (the ratio y / Y is larger) or smaller (the ratio y / Y may be smaller) from the upstream side to the downstream side in the depth direction.

  Alternatively, the radiation fin is formed so that the thickness x of the second portion 22 or the thickness X (ratio X / x) of the first portion 21 changes from the upstream side to the downstream side in the depth direction (flow direction of air) It may be done. For example, one or both of the thickness x and the thickness X may increase (or decrease) from the upstream side to the downstream side in the depth direction. In this case, the value of the ratio X / x may change along the depth direction, or the thickness x and the thickness X may change while keeping the ratio X / x constant.

DESCRIPTION OF SYMBOLS 1 core part 2 (2a-2d), 102 (102a-102d) Heat dissipation fin 10 surface 10a 1st surface 10b 2nd surface 20a, 20b side 21 and 121 1st part 22 and 122 2nd part 23 and 123 Connection part 23a, 23b, 123b inclined side part 100, 200 heat exchanger (heat exchanger for aircraft engines)
h Length of connecting part S Curved surface X Thickness of first part x Thickness of second part Y Total height of radiation fin y Height of forming position of connecting part

Claims (10)

A heat exchanger for an aircraft engine that exchanges heat with air flow in the aircraft engine, comprising:
A core portion for circulating a fluid to be cooled;
And a plurality of plate-like heat dissipating fins provided on the surface of the core portion;
The radiation fin is
A first portion rising from the surface of the core portion;
A second portion disposed distal to the first portion and having a smaller thickness than the first portion;
And a connecting portion inclined with respect to the first portion and the second portion connecting between the first portion and the second portion,
The ratio y / Y of the height y from the surface of the core portion to the formation position of the connection portion to the total height Y of the heat dissipating fins from the surface of the core portion is 0.34 <y / Y <0. A heat exchanger for aircraft engines, which is configured to meet the .64 relationship. The radiation fin is
The ratio X / x of the thickness X of the first portion to the thickness x of the second portion is formed to satisfy the relationship of 1.0 <X / x <5.4. Heat exchanger for aircraft engines. The radiation fin is
With respect to the total height Y of the radiation fin from the surface of the core portion,
The ratio h / Y of the length h of the inclined connection portion in the height direction of the heat radiation fin is formed to satisfy the relationship of 0 <h / Y <0.64. Heat exchanger for an aircraft engine as described.   The aircraft according to any one of claims 1 to 3, wherein the radiation fin has a flat side surface on one side and an inclined side surface portion of the connection portion formed on the other side surface. Heat exchanger. The radiation fin is
With respect to the total height Y of the radiation fin from the surface of the core portion,
The ratio h / Y of the length h of the inclined connection portion in the height direction of the radiation fin is formed to satisfy the relationship of 0.20 <h / Y <0.50. Heat exchanger for an aircraft engine as described.   The heat exchanger for an aircraft engine according to any one of claims 1 to 3, wherein the radiation fin is formed on both side surfaces with inclined side portions of the connection portion. The radiation fin is
With respect to the total height Y of the radiation fin from the surface of the core portion,
The ratio h / Y of the length h of the inclined connection portion in the height direction of the radiation fin is formed to satisfy the relationship of 0 <h / Y <0.40. Heat exchanger for aircraft engines.   The heat exchanger for an aircraft engine according to any one of claims 1 to 7, wherein each of the first portion and the second portion is a flat portion having a substantially constant thickness.   The heat exchanger for an aircraft engine according to any one of claims 1 to 8, wherein the heat radiation fin has a shape in which the first portion and the second portion are connected by the one connection portion. The core portion has a curved shape along a curved surface in an aircraft engine, and a hollow plate having a first surface opposite to the curved surface and a second surface opposite to the first surface. It has a shape of
The heat exchanger for an aircraft engine according to any one of claims 1 to 9, wherein a plurality of the radiation fins are formed on at least one of the first surface and the second surface.

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